import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default function htmlToPdf(title = 'content') {
    var downPdf = document.getElementById("pdfDom");
    html2Canvas(downPdf).then(function (canvas) {
        var contentWidth = canvas.width;
        var contentHeight = canvas.height;
        //一页pdf显示html页面生成的canvas高度;
        var pageHeight = contentWidth / 595.28 * 841.89;
        //未生成pdf的html页面高度
        var leftHeight = contentHeight;
        //pdf页面偏移
        var position = 0;
        //a4纸的尺寸[595.28,841.89]，html页面生成的canvas在pdf中图片的宽高
        var imgWidth = 555.28;
        var imgHeight = 555.28 / contentWidth * contentHeight;

        var pageData = canvas.toDataURL('image/jpeg', 1.0);

        var pdf = new JsPDF('', 'pt', 'a4');
        //有两个高度需要区分，一个是html页面的实际高度，和生成pdf的页面高度(841.89)
        //当内容未超过pdf一页显示的范围，无需分页
        if (leftHeight < pageHeight) {
            pdf.addImage(pageData, 'JPEG', 20, 0, imgWidth, imgHeight);
        } else {
            while (leftHeight > 0) {
                pdf.addImage(pageData, 'JPEG', 20, position, imgWidth, imgHeight)
                leftHeight -= pageHeight;
                position -= 841.89;
                //避免添加空白页
                if (leftHeight > 0) {
                    pdf.addPage();
                }
            }
        }
        pdf.save(title + '.pdf');
    })
}